1. Field of the Invention
The present invention disclosed in the present specification relates to a display unit which can display a three-dimensional image or two different images on one and the same screen.
2. Description of Related Art
Hitherto, there has been known a method of obtaining a three-dimensional image by separately perceiving an image for right eye and that for left eye by utilizing different polarization states. There has been also known a technology for obtaining a three-dimensional image by forming an image for right eye and that for left eye by utilizing two projectors and by viewing them independently by the right and left eyes (see xe2x80x9cThree-Dimensional Displayxe2x80x9d by Chihiro Masuda, Sangyo Tosho Publishing Co.).
However, there have been problems in realizing a display unit having such formation that it would be complicated, the production cost thereof would be high and their reliability would be low.
Further, because of the increased complexity and size of the whole structure thereof, it has been difficult to apply it simply as various display means. For example, the display means thereof has not been able to be applied simply to game machines, to display units of public facilities and to medical purposes. That is, because the unit itself has been complex and large, its general utility has been low.
Accordingly, it is an object of the present invention to be disclosed in the present specification to provide a display unit whose cost is low, which is highly reliable and which can display three-dimensional images, thus having an excellent general utility. Further, it is an object to provide a display unit having a formation which allows to display two different images on one screen in the same time by the same principle with the display of the three-dimensional image.
According to one invention disclosed in the present specification, a display unit has a first liquid crystal panel and a second liquid crystal panel; and means for projecting images from those two liquid crystal panels on one and the same projecting face in superposition; and is characterized in that the two liquid crystal panels have first polarizing plate and a second polarizing plate in order from a light source; and a polarizing direction of the first polarizing plate of the first liquid crystal panel and a polarizing direction of the second polarizing plate of the second liquid crystal panel are same or almost same.
The formation described above is characterized in that as shown in FIG. 2, the polarizing plates of respective two liquid crystal panels (the two liquid crystal panels are integrated by using one and the same substrate in case of FIG. 2) have a relationship as indicated by directions of arrows in the figure.
In FIG. 2, arrows 204 and 205 correspond to the polarizing directions of the first polarizing plate and arrows 206 and 207 correspond to the polarizing directions of the second polarizing plate. The above-mentioned invention is characterized in that the polarizing directions 204 and 207 of the first polarizing plate of one liquid crystal panel and of the second polarizing plate of the other liquid crystal panel are same or approximately same.
The most simplest formation among concrete formations of the above-mentioned formation is to prepare two liquid crystal panels which are totally same, to dispose one by turning by 90xc2x0 and to combine images from the two liquid crystal panels on an adequate projecting face by using an optical system.
In this case, one image is appropriated as an image for right eye and the other image as an image for left eye, for example. A stereoscopic image may be seen by seeing the images by wearing special glasses which permit to see them whose orientations differ by 90xc2x0 for the right and left eyes.
Formations shown in FIGS. 1 and 7 described later may be exemplified concretely as one example of the above-mentioned formation. The formations shown in FIGS. 1 and 7 are characterized most in that the active matrix domains which can form images, respectively, are integrated on one and the same substrate, i.e. a plurality of liquid crystal panels are combined.
According to another invention, a display unit has a first liquid crystal panel and a second liquid crystal panel; and means for projecting images from the two liquid crystal panels on one and the same projecting face in superposition; and is characterized in that the two liquid crystal panels have first polarizing plate and a second polarizing plate in order from a light source; and a polarizing direction of the second polarizing plate of the first liquid crystal panel and a polarizing direction of the second polarizing plate of the second liquid crystal panel are different by 90xc2x0 or approximately 90xc2x0.
FIG. 2 shows a concrete example of the formation described above. FIG. 2 shows the formation in which orientations of the polarizing direction 206 of the second polarizing plate of the part which corresponds to the first liquid crystal panel and of the polarizing direction 207 of the second polarizing plate of the part which corresponds to the second liquid crystal panel are different by 90xc2x0 from each other in the liquid crystal panels in which two active matrix domains are integrated.
According to still another invention, a display unit has a plurality of active matrix domains integrated by using one and the same substrate; and horizontal scan control circuits for performing horizontal scan control of the plurality of active matrix domains formed on the same substrate in common to the plurality of active matrix domains; and is characterized in that orientation films disposed on the plurality of active matrix domains are divided into two groups between which orientations are different by 90xc2x0.
FIG. 7 shows a concrete example of the aforementioned formation in which horizontal scan of the active matrix domains 703 through 705 integrated on one and the same substrate is carried out by the common horizontal scan control circuit 701.
FIG. 7 also shows a formation in which the orientation of the orientation film disposed on the active matrix domains 703 through 705 is different by 90xc2x0 from that of the orientation film disposed on the active matrix domains 706 through 708.
According to still another invention, a display unit has a plurality of active matrix domains integrated by using one and the same substrate; and vertical scan control circuits for performing vertical scan control of the plurality of active matrix domains formed on the same substrate in common to the plurality of active matrix domains; and is characterized in that orientation films disposed on the plurality of active matrix domains are divided into two groups between which orientations are different by 90xc2x0.
FIG. 1 or 7 show a concrete example of the aforementioned formation.
According to still another invention, a display unit has a plurality of active matrix domains integrated by using one and the same substrate; and horizontal scan control circuits and vertical scan control circuits for performing horizontal scan control and vertical scan control of the plurality of active matrix domains formed on the same substrate respectively in common to the plurality of active matrix domains; and is characterized in that orientation films disposed on the plurality of active matrix domains being divided into two groups between which orientations are different by 90xc2x0.
FIG. 7 shows a concrete example of the aforementioned formation.
According to one invention disclosed in the present specification, a display unit has a formation in which a plurality of active matrix domains are integrated on one and the same substrate and in which a half of the plurality of active matrix domains have first orientation means and another half of the plurality of active matrix domains have second orientation means; means for inputting linearly polarized light adjusted to the orientation means to each panel corresponding to the first and second orientation means; and is characterized in that rubbing directions are different in the first and second orientation means.
According to another invention, a display unit has a formation in which a plurality of active matrix domains are integrated on one and the same substrate; orientation means by which an orientation of at least one of the plurality of active matrix domains is different with respect to that of another active matrix domain by 90xc2x0 or approximately by 90xc2x0; and means for inputting a linearly polarized light having different polarization direction of 90xc2x0 or approximately 90xc2x0 respectively to at least one of the plurality of active matrix domains and another active matrix domain.
According to the invention disclosed in the present specification, the display unit is characterized in that at least two horizontal scan controls of the plurality of active matrix domains are carried out by a common horizontal scan control circuit in the integrated liquid crystal panels.
Further, the display unit is characterized in that at least two vertical scan controls of the plurality of active matrix domains are carried out by a common vertical scan control circuit in the integrated liquid crystal panels.